A first design involves a push-button valve with catch function. To start irrigation, the valve button is pushed down and remains in a catch position. To switch the irrigation off, the valve button has to be pushed down again.
In a second design, a so-called press-down valve, irrigation (or, if appropriate, suction) takes place only with the valve button being kept pressed down.
Such a press-down valve forms the subject of the present invention.
In practical use, contaminants can get into the press-down valve, so that it is necessary to clean and sterilize the press-down valve after each use.
To do so, it is customary for the press-down valve to be arranged in a releasable manner on the medical suction and irrigation instrument, so that it can be removed, for example unscrewed, for the cleaning procedure.
Because of their construction, a problem with press-down valves is that the valve stem is always pressed into its closure position. When one wants to clean the press-down valve, it is necessary to activate the valve stem in order to bring the latter into its open position, so that the cleaning liquid can be flushed through the inside of the valve body.
This is extremely difficult to do in the press-down valves, because the spring, pretensioned with quite considerable force, presses the valve stem into the closure position.
It should also be noted that such a press-down valve has dimensions of only a few centimeters, which means that, while holding the press-down valve in one's hand, it is very difficult to keep it in the open position, by pressing the actuation element, and at the same time carry out irrigation.
For construction-related reasons, automated irrigation/cleaning of a press-down valve already dismantled from the medical instrument cannot be performed, because flushing in the open position of the valve stem is not possible. To do this, the press-down valve would have to be installed again in a kind of holder that simulates actuation of the press-down valve, which would be very complicated and extremely laborious.
Therefore, it is an object of the present invention to develop a press-down valve in such a way that it can be easily cleaned.